TR TF-X KAAN Fighter Jet

Spitfire9 said:

Your assessment of probability is unusual.

My understanding is that the prototypes being built are design development airframes, subject to change, rather than 'identical' aircraft to test a frozen design.

Out of curiosity, a prototype aircraft exists that moves under its own power on the ground and was projected to fly last year, so why do you think it will be several years before it flies?

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I am sorry, but your understanding is incorrect. CDR is conducted to establish a product baseline which is basically used as a reference of final detailed design of aircraft and this applies to not only airframes, but also electrical and avionics subsystems & their integration and implementation and so on. It also finalizes acceptance criteria for performance test and may conclude production guidlines before it goes for 2000+ sorties of actual flight tests.

So no, you reallly don't want to fly aircraft before CDR. It is not rational.

Hurjet flew a few years after completion of CDR as far as I know. So did many aircraft before it. I don't see how could Kaan be any different.

Isbara said:

Whith who and which facility are they going to design the engine ?
If so why Prf. Aksit expressed that they're working on TF-35000 ? Also added In they're trying to develop and test on TF10000, the tech they're going to use on TF35000.
So what is TEI developing for TF35000 if it is TR-Motor to design engine ? This project had become a nutshell already.

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It is like TR Motor exists for nothing, ha.

Dosirak said:

I am sorry, but your understanding is incorrect. CDR is conducted to establish a product baseline which is basically used as a reference of final detailed design of aircraft and this applies to not only airframes, but also electrical and avionics subsystems & their integration and implementation and so on. It also finalizes acceptance criteria for performance test and may conclude production guidlines before it goes for 2000+ sorties of actual flight tests.

So no, you reallly don't want to fly aircraft before CDR. It is not rational.

Hurjet flew a few years after completion of CDR as far as I know. So did many aircraft before it. I don't see how could Kaan be any different.

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I am aware that CDR acceptance is normal before embarking on prototype building. As far as I know Kaan development does not fit the norm.

Having built the first prototype, what would be the point of waiting to fly it if it is ready to fly and start gathering flight performance data? Perhaps it is not ready for flight. Perhaps it is being kept on the ground for political reasons, only to leave the ground at some politically auspicious moment before the upcoming elections?

Spitfire9 said:

Having built the first prototype, what would be the point of waiting to fly it if it is ready to fly and start gathering flight performance data?

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2nd prototype. Which is the one originally slated to fly before all these election shenanigans came to be.

Proto 2 should be in FAL. We have seen its parts getting produced in 2023 Summer

Spitfire9 said:

Your assessment of probability is unusual.

My understanding is that the prototypes being built are design development airframes, subject to change, rather than 'identical' aircraft to test a frozen design.

Out of curiosity, a prototype aircraft exists that moves under its own power on the ground and was projected to fly last year, so why do you think it will be several years before it flies?

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I am not talking about Kaan; but the delay of flight is normal.

For example, the Su-27 was delayed for many years for redesign because the initial design couldn’t be matched to F-15.

Also the Japanese Mitsubishi X-2 Shinshin was expected to conduct its maiden flight in 2014; but delayed to 2016.

Heartbang said:

2nd prototype. Which is the one originally slated to fly before all these election shenanigans came to be.

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I think a Metro line and bread price are more important than Jet fighter in local election(not the national election)

Heartbang said:

2nd prototype. Which is the one originally slated to fly before all these election shenanigans came to be.

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I don't understand. Why build a first prototype, roll it out, taxi it around but wait until a second prototype is built before flying the type?

Spitfire9 said:

I don't understand. Why build a first prototype, roll it out, taxi it around but wait until a second prototype is built before flying the type?

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Ground tests are at least as important as tests made during flight. Also ground test prototypes go through scrutinised tests under extreme conditions which aren't exactly things you'd do when the prototype is airborne. The ground tests could result in some minor structural changes, i.e. reinforcements, weight/balance/vibration issues amongst other things. Extreme pressure tests, lightning resistance tests etc.
After all these tests I think flying that same thing would be a great risk, not to mention that it's not built to fly anyway that means it has many components and electronics left out.
Baykar for example has flown all their prototypes AFAIK, but there's no risk of losing a pilot in their case, plus they have a different approach compared to TAI.

Spitfire9 said:

I don't understand. Why build a first prototype, roll it out, taxi it around but wait until a second prototype is built before flying the type?

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Maybe they found some problems needed to fix

KAAN is our first jet fighter we have to do lot of issues.

Spitfire9 said:

I am aware that CDR acceptance is normal before embarking on prototype building. As far as I know Kaan development does not fit the norm.

Having built the first prototype, what would be the point of waiting to fly it if it is ready to fly and start gathering flight performance data? Perhaps it is not ready for flight. Perhaps it is being kept on the ground for political reasons, only to leave the ground at some politically auspicious moment before the upcoming elections?

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Because CDR has not been completed and (initial) product baseline has not been established. What's point of gathering 'flight performance data' when acceptance criteria for HW & SW has not been reviewed & confirmed? Comparing the date to what? How about risk management & mitigation plan? I think you completely misunderstand the whole purpose of flight tests.

The aircraft you see today is not an actual 'prototype' and it doesn't matter if it flies today, tomorrow or anytime this year - the flight is essentially moot.

TAI is going to do CDR of Kaan anyway and with this TAI will manufacture & test a prototype in accordance with the guidelines that are established by the initial product baseline. That will be the moment that actual flight testing starts.

Dosirak said:

Because CDR has not been completed and (initial) product baseline has not been established. What's point of gathering 'flight performance data' when acceptance criteria for HW & SW has not been reviewed & confirmed? Comparing the date to what? How about risk management & mitigation plan? I think you completely misunderstand the whole purpose of flight tests.

The aircraft you see today is not an actual 'prototype' and it doesn't matter if it flies today, tomorrow or anytime this year - the flight is essentially moot.

TAI is going to do CDR of Kaan anyway and with this TAI will manufacture & test a prototype in accordance with the guidelines that are established by the initial product baseline. That will be the moment that actual flight testing starts.

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I defer to your better knowledge. However, from the mouth of the head of TAI in mid- December I heard that TAI were still aiming for the 27th December as FF date. In January I heard FF would be in days IIRC. No mention that CDR had been completed. No mention of waiting for completion of CDR before FF 27th December. No mention in January of waiting for completion of CDR before FF in a few days.

Earlier this month Mr Kotil said Kaan FF would be in the coming days. You said it will be in years. Perhaps you can understand why I bemused.

PS Kaan is not important to me in terms of my national security. The RAF is not anticipating putting Kaan into service. I do, however, have an interest in aviation, so I am interested in following progress in the project, including when Kaan's FF is likely to be.

Spitfire9 said:

I defer to your better knowledge. However, from the mouth of the head of TAI in mid- December I heard that TAI were still aiming for the 27th December as FF date. In January I heard FF would be in days IIRC. No mention that CFR had been completed. No mention of waiting for completion of CDR before FF 27th December. No mention in January of waiting for completion of CDR before FF in a few days.

Earlier this month Mr Kotil said Kaan FF would be in the coming days. You said it will be in years. Perhaps you can understand why I bemused.

PS Kaan is not important to me in terms of my national security. The RAF is not anticipating putting Kaan into service. I do, however, have an interest in aviation, so I am interested in following progress in the project, including when Kaan's FF is likely to be.

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Well, the head of TAI either misled the people or simply lied.

However, when the Air Forces Command of Turkey presented a timeline of TF-X development in 2021, it was clearly stated that CDR would be completed in late 2024 and 'First Flight' would be conducted in late 2026.

Dosirak said:

Well, the head of TAI either misled the people or simply lied.

However, when the Air Forces Command of Turkey presented a timeline of TF-X development in 2021, it was clearly stated that CDR would be completed in late 2024 and 'First Flight' would be conducted in late 2026.

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You are remembering correctly, and that plan is still more or less the same, albeit it has been brought forward a bit. They are planning to carry out CDR later this year and roll out their first EMD prototype with actual mission critical avionics in the later years.

What we see today, the GTU-0, is more or less a developmental technology demonstrator. It doesn't have any of the mission critical avionics and had not even the flight computer until very recently.

Think about it this way. Turkiye until now has never developed a manned, supersonic aircraft, let alone a stealth fighter which also has aforementioned attributes. It actually needs some experience in terms of flight control design, as well as low observable planfrom design and evaluation capabilities. Had they took a more "sensible" route, they might have first developed Hurjet, gain experience in these matters and then proceed with a development of state-of-the-art 5th gen fighter, but that's unfortunately not an option for Turkiye.

Safe to say, the project management as well as outline of MMU program is pretty rough, considering all the changes to the program schedules mid-course, as well as its inherent risks, but conversely, I also personally think that it is actually pretty wise to use GTU-0 as a TD (although Turks call it a "prototype", which is not wrong in a literal sense, but considering how the term is commonly used, this thing is not a conventional "prototype" as you've said. Which is also the reason I'd say that you ain't wrong in saying that Temel Kotil is misleading people in a way.).

I'd describe GTU-0 and the next "prototype" under construction atm to be more similar to YF-22, ACX and EAP. The actual EMD prototype will only follow after CDR.

Thanks for the info, all concerned. If the aircraft being built are what would be best described as technical demonstrators, that paints a different picture of the project to the one that I was seeing.

Since we've got a chance here, I would like to discuss a bit more about what the Turks would be able to do with GTU-0.

Other than it being a great learning experience for TAI engineers in terms of design and development of flight controls and dynamics, as I've mentioned in above post, the opportunity it provides in terms of what Turkiye can learn in LO design could be very critical.

For instance, I could already think of a very basic radar observability evaluation campaign where they could fly the GTU-0 while tracking it with various airborne assets like F-16 and E-737, as well as surface based radars of Siper system and I-class.

These kinds of campaigns would probably not get public, but could definitely happen. It would provide very useful real world data concerning how the actual MMU planform performs against real fighter FCR operating in X band, AEW&C radar operating in L band, and various surface based MFR. Conversely, it would showcase how the newest gen Turkish radars perform agains LO targets.

Furthermore, it could be used as a testbed for various stealth materials like Turkish RAM. They could, for instance, test the RAM coated canopy glass on the GTU-0, akin to how the US tested Have Glass canopy before applying it to operational units. This would free the actual EMD prototypes from more mission critical performance evaluations.

To be honest, when I first beard that TAI decided to fly GTU-0, I thought it was mostly a publicity stunt, since in my view it made no sense to take a ground static test vehicle and make it fly, all the while the CDR is incomplete. Though the more I think about it, the more I see the benefits and opportunities. It would certainly mean higher development cost, though now it seems more like a risk-management measure more than anything else, which is quite ironic.

They are basically taking more risk now (of losing the aircraft) to gain crucial knowledge and know-how. No wonder TAI and SSB have very different positions regarding GTU-0. TAI wants to risk it considering the possible gains, since it's kore or less merely a TD. Loss of GTU-0 wouldn't be that critixal compared to the loss of an actual EMD prototype. On the other hand, being bureaucrats, SSB wouldn't want any of the headaches of possible loss of aircraft. The risks of losing GTU-0 in flgiht tests seems very real and present.

Lastly, what I could say with absolute confidence is that the test pilots are taking the biggest risk here, flying a prototype that wasn't supposed to fly, a plane that hasn't gone through ground static tests, a plane controlled by one of the first Turkish flight control system of this scale, bar Hurjet. You guys probably have a great deal of respect for those TAI pilots, but I think they deserve it even more flying this thing.

Windchime said:

Since we've got a chance here, I would like to discuss a bit more about what the Turks would be able to do with GTU-0.

Other than it being a great learning experience for TAI engineers in terms of design and development of flight controls and dynamics, as I've mentioned in above post, the opportunity it provides in terms of what Turkiye can learn in LO design could be very critical.

For instance, I could already think of a very basic radar observability evaluation campaign where they could fly the GTU-0 while tracking it with various airborne assets like F-16 and E-737, as well as surface based radars of Siper system and I-class.

These kinds of campaigns would probably not get public, but could definitely happen. It would provide very useful real world data concerning how the actual MMU planform performs against real fighter FCR operating in X band, AEW&C radar operating in L band, and various surface based MFR. Conversely, it would showcase how the newest gen Turkish radars perform agains LO targets.

Furthermore, it could be used as a testbed for various stealth materials like Turkish RAM. They could, for instance, test the RAM coated canopy glass on the GTU-0, akin to how the US tested Have Glass canopy before applying it to operational units. This would free the actual EMD prototypes from more mission critical performance evaluations.

To be honest, when I first beard that TAI decided to fly GTU-0, I thought it was mostly a publicity stunt, since in my view it made no sense to take a ground static test vehicle and make it fly, all the while the CDR is incomplete. Though the more I think about it, the more I see the benefits and opportunities. It would certainly mean higher development cost, though now it seems more like a risk-management measure more than anything else, which is quite ironic.

They are basically taking more risk now (of losing the aircraft) to gain crucial knowledge and know-how. No wonder TAI and SSB have very different positions regarding GTU-0. TAI wants to risk it considering the possible gains. On the other hand, being bureaucrats, SSB wouldn't want any of the headaches of possible loss of aircraft. The risks of losing GTU-0 in flgiht tests seems very real and present.

Lastly, what I could say with absolute confidence is that the test pilots are taking the biggest risk here, flying a prototype that wasn't supposed to fly, a plane that hasn't gone through ground static tests, a plane controlled by one of the first Turkish flight control system of this scale, bar Hurjet. You guys probably have a great deal of respect for those TAI pilots, but I think they deserve it even more flying this thing.

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For this exact reason, delays with GTU-0 are more than normal, even more so than the actual prototypes, and giving it a set date of first flight was always wrong.

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Playing the devil's advocate, if we had few F-35s flying around nowadays, we probably wouldn't do this. As we could just use the F-35s in the same role.

How many more times we need to hear that delays are totally normal? I believe it's been already said 40 times, everyone must have believed it by now. (My apologies for the ambiguity to the non-Turkish readers).

Windchime said:

To be honest, when I first beard that TAI decided to fly GTU-0, I thought it was mostly a publicity stunt, since in my view it made no sense to take a ground static test vehicle and make it fly...

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Frame #0 was supposed to be a static test frame??? It sounds like it got waylaid somewhere along the line by non-engineering considerations.

Sanchez said:

Playing the devil's advocate, if we had few F-35s flying around nowadays, we probably wouldn't do this. As we could just use the F-35s in the same role.

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Possibly. The learning experience regarding supersonic aircraft design and control could be gained with Hurjet, that's for sure.

It would've been better if Hurjet development started a few years earlier, which would've provided TAI engineers more time to learn flight controls. The demand was always there ever since the TX-FX days, and they could've begun as early as when TAI was participating in T-X with SNC.

There always was the need to replace aging T-38s in THK, so it's kinda hard to understand why Turkiye decided to wait until 2017. I know that Hurjet is an internally funded project by TAI, but it's still counterintuitive nonetheless.

Though, I should note that usong F-35 wouldn't have provided as much design experience and LO know-how. It would've provided critical insights into the nature of the most advanced, network-centric stealth fighter, but conversely, it wouldn't have provided TAI any design experiences. There are some obvious pros and cons. You should lose one wide to gain another.